ACPAtmospheric Chemistry and PhysicsACPAtmos. Chem. Phys.1680-7324Copernicus PublicationsGöttingen, Germany10.5194/acp-5-1291-2005Rapid meridional transport of tropical airmasses to the Arctic during the major stratospheric warming in January 2003KleinböhlA.12KuttippurathJ.1SinnhuberM.1SinnhuberB.-M.1KüllmannH.1KünziK.1NotholtJ.11Institute of Environmental Physics, University of Bremen, Bremen, Germany2now at: Jet Propulsion Laboratory, Pasadena, CA, USA010620055512911299This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article is available from http://www.atmos-chem-phys.net/5/1291/2005/acp-5-1291-2005.htmlThe full text article is available as a PDF file from http://www.atmos-chem-phys.net/5/1291/2005/acp-5-1291-2005.pdf

We present observations of unusually high values of ozone and N<sub>2</sub>O in the middle stratosphere
that were observed by the airborne submillimeter radiometer ASUR in the Arctic.
The observations took place in the meteorological situation of a major stratospheric warming
that occurred in mid-January 2003 and was dominated by a wave 2 event.
On 23&nbsp;January 2003 the observed N<sub>2</sub>O and O<sub>3</sub> mixing ratios around 69&deg; N
in the middle stratosphere reached maximum values of ~190&nbsp;ppb
and ~10&nbsp;ppm, respectively.
The similarities of these N<sub>2</sub>O profiles in a potential temperature range
between 800 and 1200&nbsp;K
with N<sub>2</sub>O observations around 20&deg; N on 1&nbsp;March 2003 by the same instrument
suggest that the observed Arctic airmasses were transported from the tropics
quasi-isentropically. This is confirmed by 5-day back trajectory calculations
which indicate that the airmasses between about 800 and 1000&nbsp;K had been located around 20&deg; N
3&ndash;5 days prior to the measurement in the Arctic.
Calculations with a linearized ozone chemistry model along calculated as well as idealized trajectories,
initialized with the low-latitude ASUR ozone measurements, give reasonable agreement with the Arctic
ozone measurement by ASUR.
PV distributions suggest that these airmasses did not stay confined
in the Arctic region which makes it unlikely that this
dynamical situation lead to the formation of dynamically caused pockets of low ozone.